It was his son Garrett’s 10th birthday party, and Mike Webster was nowhere to be found. When the celebration began, Webster lay motionless, incapacitated by a combination of various medications, on a bed in a Budget Inn 20 minutes down the road.

With his illustrious, 17-year NFL career as a Pittsburgh Steelers center now only a memory, Webster had little to show for his success. The former NFL great was resisting help from friends and family, and had been reduced to homelessness. He was living on potato chips and dry cereal, and shocking himself into unconsciousness with a black Taser gun in order to get any sort of sleep. A shadow of the legend they called “Iron Mike,” Webster was now an entirely different person. In September 2002, his slow and tragic decline came to a close when he died of heart failure in a Pittsburgh hospital.

Later that year, pathologist Bennet Omalu performed an autopsy on Webster with the permission of Webster’s family. Having heard reports of Webster’s behavior, Omalu was surprised to find during the initial autopsy that Webster’s brain “looked normal.” Later, however, when he examined the brain in greater detail, Omalu noticed “smudges and tangles” of a protein called “tau.” The tangles appeared “similar to those that would be seen in Alzheimer’s disease,” but were not accompanied by other substances that are typically present in the brain of an Alzheimer’s patient. Upon further investigation, Omalu concluded that Webster had suffered from the brain disease chronic traumatic encephalopathy, or CTE.

Mike Webster is one of a growing number of former football players diagnosed in the last decade with CTE, a disease once thought to be limited to boxers. CTE is characterized by “progressive degeneration” […]